How to Override 'to string' Representation of a Class Object in Python

Python - Override 'to string' Representation of a Class Object

To override string representation of a class object in Python, define __str__(self) function and return the required string.

Example

Let us consider a class named Fruit as shown in the following without overriding __str__(self) function.

class Fruit:
    name = ''
    quantity = ''
    description = ''
    
    def __init__(self, name, quantity, description):
        self.name = name
        self.quantity = quantity
        self.description = description

In the following example, we create an object of type Fruit, and print the object to console.

Python Program

class Fruit:
    name = ''
    quantity = ''
    description = ''
    
    def __init__(self, name, quantity, description):
        self.name = name
        self.quantity = quantity
        self.description = description

apple = Fruit('Apple', '58', 'Good for health.')
print(apple)

Output

<__main__.Fruit object at 0x1025abc10>

The string representation is difficult to read.

Now, we shall override the __str__(self) function and return a string that specifies the attributes in detail.

Python Program

class Fruit:
    name = ''
    quantity = ''
    description = ''
    
    def __init__(self, name, quantity, description):
        self.name = name
        self.quantity = quantity
        self.description = description

    def __str__(self):
        details = ''
        details += f'Name        : {self.name}\n'
        details += f'Quantity    : {self.quantity}\n'
        details += f'Description : {self.description}\n'
        return details

apple = Fruit('Apple', '58', 'Good for health.')
print(apple)

Output

Name        : Apple
Quantity    : 58
Description : Good for health.

Summary

In this Python Classes and Objects tutorial, we learned how to override __str__() function in a class definition to change the string representation of a class object.

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